Fuel issues

Discussion in 'Mechanics Garage' started by Grae1965, Aug 21, 2020.

  1. Grae1965

    Grae1965 New Member

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    Hi,ive got an 86 vf500 and struggling with not getting fuel into carbs. It runs from petcock to t-piece fine,but from t-piece to carbs something is going wrong. Ive undone carb drains and nothing comes out,she starts ok if i put fuel directly into carbs via air filter(removed). Shes been standing a couple of years so am i correct to assume that its just a build up of crap? Please someone out in Vf land help,im so wanting to make her as good as i possibly can
     
  2. BoomerDave

    BoomerDave New Member

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    Have you bench tested the fuel pump ?
    You can bypass it by running a line from the petcock directly to the carbs to verify the petcock functions.
    If fuel still won't flow, pull the petcock and inspect/rebuild it.
     
  3. BoomerDave

    BoomerDave New Member

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    I see I have replied to two separate threads by you on this topic.
     
  4. squirrelman

    squirrelman Member

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    you could try blowing compressed air through the lines. also, the small filters just above the float needle seats might be clogged.
     
  5. Dannoxyz

    Dannoxyz New Member

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    No fuel-pump on '86 VF500F, only '84-85 had pumps. Gravity-feed works fine on '86

    Float valves can also stick to their seats after sitting for while. If sat over 6-months, I suggest full carb rebuild:

    - split carbs, replace all fuel-rail O-rings, completely disassemble Z-pipe.
    - fully scrub all fuel-circuits with nylon scrub brushes and PEA- based fuel-system cleaner
    - poke out all bleed holes in jets, pilot, emulsion tube, carb venturi with matching size soft copper wire
    - soak all parts in ultrasonic cleaner for hours using non-polar solvent
    - micro soda blast all jets, fuel-circuits, bleed holes
    - replace pilot O-rjngs when re-assembling
    - replace float valves
    - replace float valve seats if face not OK
    - set float levels
    - replace float bowl seals

    I’ve owned 10 VF500Fs 84-86 models over years since my 1st brand-new 1986 model in 1987. Which I still own to this day. Along with 5 VFRs of various generation.

    I got sick of pulling carbs 4-5 times for ever deeper cleaning until it finally ran right. Now I just do full restoration job very 1st time around. Saves so much time and effort to get carbs back to factory-new clean condition. Bike runs like it just left showroom floor!
     
    Last edited: Sep 15, 2020
  6. bigbadbass

    bigbadbass New Member

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    @Dannoxyz deja vu? VFR in my avatar look remotely familiar?
     
  7. Dannoxyz

    Dannoxyz New Member

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    Hi, is that you ducatiman? How'd you end up with my bike?

    [​IMG]
     
  8. bigbadbass

    bigbadbass New Member

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    Yup. Your bike? its MINE! :) When you geddit?

    vfr2020.jpg
     
    Last edited: Sep 15, 2020
  9. Dannoxyz

    Dannoxyz New Member

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    I got it like 5-years ago and sold it last year after riding it 3x in prior year.

    I like specialised scalpel-focused bikes for each type of riding. Ninja 250s for commuting so I can slip through traffic and split easily. CBR600RR for canyon-carving rides. Both Ninja 250s and CBR for trackdays and racing.

    VFR was jack-of-all-trades that did everything well, but wasn’t best at anything. I always ended up selecting one of other bikes for each type of ride I did. Sad to see it just sitting around collecting dust, so I sent it on its way to someone else who will ride it more! :)


    At this point, if I end up doing 2-up touring, I will get ST1300!
     
  10. Diving Pete

    Diving Pete Insider

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    Also had a couple of ninja 250's - for getting through traffic they are awesome.. Over a 20 mile commute I was on average only 2 minutes quicker on my Blade than the 250..
    Also ridiculous MPG..
     
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